A mobile communications network generally uses a cellular system, that is, different base stations are set up in different places, where each base station forms a cell, and is responsible for communication of mobile users in the place. Some hotspot areas with a large communication traffic volume exist in a general mobile communications network. In order to provide a larger system capacity for the hotspot areas, micro cells are generally set up in the hotspot areas, and services are provided to mobile users in the hotspot areas by using the micro cells.
Therefore, a mobile communications network is generally a heterogeneous network (Het Net). First, a macro cell is established by using a macro base station to implement a large range of continuous network coverage, and then a micro cell is established in a hotspot area by using a micro base station to perform coverage overlapping, where the micro cell provides a larger system capacity.
System information broadcast is an important function in a communications system, and mainly provides main information of an access network system, so that user equipment (UE) establishes a wireless connection. System information in the system information broadcast is a link connecting UE and a network, and the UE and an evolved universal terrestrial radio access network implement various types of services and physical processes of wireless communication by means of the system information transmission.
In many technologies, message broadcast is strongly regional. For example, during discovery of a small cell, most of the time, system information is required for providing small cell information of a neighboring cell, such as a physical cell identifier, frequency information, or reference signaling information, and device-to-device (D2D) communication user equipment needs to determine whether there is an available resource in a surrounding area of the D2D communication user equipment.
In an existing message broadcast method, same system information is generally broadcast to all UEs in a cell to save a radio resource; therefore, system information that is generated due to a requirement of a new technology cannot be reduced. In addition, user equipment may therefore receive a message unrelated to the user equipment, and trigger unnecessary behavior.